This invention relates to a method and an apparatus for feeding a plurality of fiber processing machines, such as carding machines, rollercard units and the like wherein fiber tufts are pneumatically delivered through a tuft conveyor duct to a plurality of collecting chutes where the fiber tufts deposited therein are pneumatically compressed by a fan-generated air stream and wherein each chute has a predetermined fill level for the fiber material. The supply of fiber tufts to the collecting chutes is effected by a fiber tuft delivering apparatus wherein the pressure in the conveyor duct or in the collecting chute is sensed and regulated.
In order to be able to compress relatively large fiber tufts with a relatively low air resistance, a fan with a relatively high output is required. If in the same tuft feeder easily compressible tufts (relatively small fiber tufts) are to be processed and, in particular, if the machine should be able to operate with both types of fiber tufts in an alternating manner, according to a known method, at the beginning of the tuft processing, the setting of the pressure sensor which responds to the pressure in the collecting chute (filling chute or feed chute) is manually altered. The pressure sensor is connected by means of a regulator with the drive motor for the feed roller of the tuft feeder whereby the quantity of the fiber material supplied to the feed chute is varied. In such a mode of operation, the fill level of the fiber material column in the feed chute always varies which thus also means an alteration of the degree the air outlet openings provided in the feed chute are covered by the fiber material. It is a disadvantage of this arrangement that a deviation from an optimal fill level or optimal coverage of the air outlet openings for the best compression effect will occur.